Monitoring systems for supervising the status of various conditions in a selected region are useful in protecting property and individuals in the region. Representative systems include premises mounting systems such as burglar detection or fire detection systems. One such system is disclosed and claimed in Tice et al. U.S. Pat. No. 4,916,432 entitled Smoke and Fire Detection System Communication.
In addition to monitoring the region, it is desirable for the system to be able to supervise its constituent components. Where ambient condition detectors are present, detector supervision circuits are useful. It would be preferable, however, if routine maintenance could be distinguished from a fault condition.